Other Notes

NetApp's embedded operating system processes NFS requests from the network layer without any NFS daemons, and uses non-volatile memory to improve performance.

The tested system was a Data ONTAP GX System comprised of 24 FAS6070 nodes joined by cluster network N2.

Cluster Details:

Each node had access to the client network (N1) for communication with all load generators.

Each node had access to the cluster network (N2) for communication with the other nodes.

Each node was the owner of a single disk pool or "aggregate", composed of five RAID-DP groups, each composed of 14 data disks and 2 parity disks. A separate aggregate consisting of 3 disks in a single RAID-DP group was created on each node to hold the Data ONTAP GX operating system files. Each node was also allocated a spare disk.

Each flexible volume was mapped to a subdirectory of the global namespace under root (/vol1, /vol2, ... , /vol24).

For UAR compliance, the processes on each client uniformly mounted 24 different flexible volumes from the single namespace. On each client, one of the processes accessed a volume that resided on the node which it was directly mounting. The other 23 processes accessed their assigned flexvols through nodes which did not reside on the node that was directly mounted. The resulting access pattern was such that 1/24th of all accesses to each volume were made through the node that hosted the volume, and 23/24th of all accesses were made through nodes which did not host the volume and were transferred to the hosting node via the cluster network.

Each disk controller had two 2Gbit/s FC-AL ESH2 (Electronically Switched Hub) loops, both loops were active. Each disk was attached to two loops, one from each controller so that, in the event of a controller or loop-fault, the disk could be controlled by the surviving controller.